Infants who sleep less may have lower cognitive and language skills by age two

Does your child sleep less than 12 hours over a 24-hour period? Does he or she breathe through the mouth, snore or have pauses in breathing while asleep?

New CHILD Study research has examined the impact of an infant’s sleep duration and sleep disruption due to sleep-disordered breathing (SDB) on cognitive and language development at two years of age.

“Short sleep duration and symptoms of SDB ranging from snoring to sleep apnea have been associated with multiple health, learning and behavioural problems in children,” says
Dr. Piush Mandhane
, an associate professor of pediatrics in the University of Alberta’s (U of A) Faculty of Medicine & Dentistry, and leader of the CHILD Study’s Edmonton site. “Our study aimed to find out if limited sleep time and sleep disruption affected cognitive and language development in preschool children.”

The researchers found that infants who regularly sleep less than 12 hours total over a 24-hour period have poorer cognitive and language development at two years of age than infants who get more sleep.

They also found that nighttime sleep had a greater impact on cognitive and language development compared to daytime sleep, and a short nighttime sleep was associated with a decrease of roughly 10 points in cognitive development using a standardized test of mental and motor development. “The difference was significant,” says Dr. Mandhane.

The researchers further found that children with persistent SDB had lower language scores, but no differences in cognitive development compared to children with no SDB. AllerGen trainee Dr. Lisa Smithson (University of Alberta), the study’s first author, suggests a few possible explanations for this finding.

“One theory is that language acquisition is more sensitive to sleep disruption than cognitive development. Alternatively, the link between SDB and language delay may be the result of kids having multiple nose and ear infections, which tend to impair hearing and speech,” she says.

In a second study, Dr. Mandhane and the CHILD research team identified four patterns of SDB from infancy to two years of age and unique risk factors associated with each.

“We found that infants who received medication for acid reflux were more likely to have early-onset SDB, while children who were exposed to smoke or dogs in the home were more likely to develop late-onset SDB. Children at risk for allergies or with divorced parents were more likely to present with persistent SDB,” explains Dr. Mandhane.

Both papers were published in the August 2018 issue of Sleep Medicine and will help doctors better predict which children are at risk for sleep disorders and intervene early with treatment.

Press release